1. Field of the Invention
The present invention relates to a use of 15-keto-prostaglandin E or F compounds for uterine contraction.
Prostaglandins (hereinafter, prostaglandin is referred to as PG ) are members of a class of organic carboxylic acid that are contained in human and most other mammalian tissues or organs and that exhibit a wide range of physiological activities. Naturally occurring PGs possess as a common structural feature the prostanoic acid skeleton: ##STR1## while some of synthetic analogues have somewhat modified skeletons. The natural PGs are classified based on the structual feature of five-membered cycle moiety into PGAs, PGBs, PGCs, PGDs, PGEs, PGFs, PGGs, PGHs, PGIs and PGJs, and also on the presence or absence of unsaturation and oxidation in the chain moiety as:
Subscript 1--15--OH PA1 Subscript 2--5,6-unsaturated--15--OH PA1 Subscript 3--5,6-- and 17, 18-diunsaturated--
Further, PGFs are sub-classified according to the configration of hydroxy groups at 9- and 11-position into .alpha.(both hydroxy groups being in alpha configration) and .beta.(both hydroxy groups being in beta configration).
2. Background Information
Natural PGE.sub.1, PGE.sub.2 and PGE.sub.3 are known to have vasodilating, hypotensive, gastro-juice reducing, intestine-hyperkinetic, uterine contracting, diuretic, bronchodilating and anti-ulcer activities. Also, natural PGF.sub.1.alpha., PGF.sub.2.alpha. and PGF.sub.3.alpha. are known to have hypertensive, vasocontracting, intestine-hyperkinetic, uterine contacting, luteo-regressive and bronchocontracting activities. Among others, PGF.sub.2.alpha. is put into practical use as parturifacient and also is known to have anti-pregnant activity. However, application of PGF.sub.2.alpha. is limited by its undersirable side-effects, i.e. intestine-contracting and intraocular hypertensive activities.
In addition, some 15-keto (i.e. having an oxo group at. 15-position in place of the hydroxy group) prostaglandins and 13,14-dihydro-15-keto-prostaglandins are known as substances naturally produced by enzymatic actions during metabolism of natural PGs (Acta Physiologica Scandinavica, 66, 509, 1966). It has also been described that 15-keto-prostaglandin F.sub.2.alpha. has an antipregnant activity.